Frequency translating backscatter modulator with envelope control to support OFDM/QAM and other envelope modulated wireless protocols

摘要

A backscatter modulator for providing low power wireless communications. The disclosed modulator provides phase control for discriminating backscatter from the antenna versus other objects. In addition, the disclosed backscatter modulator provides amplitude modulation so that the technique can provide a non-constant envelope which can provide an intentional imbalance to manipulate super-position to provide envelope control of the reflected signal, while still maintaining the frequency translation properties. The disclosed backscatter modulator thus allows compatibility with QAM, OFDM and other non-constant envelope modulation schemes to be backscattered, while still supporting the frequency translation behavior.